CROSS-SECTIONS FOR PRODUCTION OF H(2P, 2S, 1S) BY ELECTRON COLLISIONAL DISSOCIATION OF H-2

We have measured the excitation function of H Ly-alpha produced by dissociative excitation of H-2 at energies 10-700 eV. The branches of the reaction have been separated using analytic models to fit the measured total excitation function. Strong threshold resonances by triplet states account for the sharp cross section rise at threshold, 14.7 eV. Above thresholds to 25 eV the e3-SIGMA-u+ state makes the largest contribution to the H Ly-alpha emission cross section by direct dissociation and predissociation of the d 3-PI-u state. The excitation function displays structure at approximately 30 eV which can be attributed to the production of fast (almost-equal-to 4 eV) H(2l) atoms from doubly excited states. Above 50 eV predissociation of the singlet states (D, D', B") by the B' state accounts for the largest contribution of the H Ly-alpha emission cross section. The yield of H(2p), H(2s), and H(1s) atoms contributing to the dissociation of H-2 into H(2l) and H(1s) atoms including cascade components was calculated from the measurements to be 33% +/- 5%, 23% +/- 4%, and 44% +/- 6%, respectively, at 100 eV.